Sewing an Envelope-Style Pillow Sham for a 16-Inch Square Insert

How to Make a Cover for a 16x16 Pillow

Use square throw pillows on your bed as well as on a sofa.

There are two reasons to sew your own throw pillow covers. First, because they come off, you can wash or dry clean them whenever they get soiled. Second, since swapping covers is simple, you can refresh a room's appearance whenever the current look starts to feel stale. Choose a fabric that works with your decor, along with trim that pairs well with it. With a bit of practice, a single cover comes together in about an hour.

Step 1: Measure and Mark

Place the fabric on a flat work surface with the wrong side — the face that will end up hidden inside the finished cover — turned downward. Using a tape measure and a fabric marker, measure out and mark these pieces: one square measuring 17 inches per side, and two rectangles each measuring 17 by 10 1/2 inches.

Step 2: Cut the Fabric

Use scissors to cut out all three pieces. The square becomes the front of the cover, while the two rectangles overlap each other on the back, creating the opening where the pillow form goes in.

Step 3: Fold and Press

Take one rectangle and fold one of its long edges 1/2 inch toward the wrong side. Press the fold with an iron. Then fold that same edge another 3/8 inch in the same direction and press it again.

Step 4: Pin Along the Foldover

With the wrong side of the fabric facing you, one long edge should now show a 3/8-inch foldover of the fabric's right side. Pin along this foldover with straight pins set perpendicular to the edge and spaced roughly 3 inches apart.

Step 5: Repeat and Sew

Do the same to the second rectangle. Then stitch along the edge of each foldover on the sewing machine, pulling out pins as you advance.

Step 6: Pin the Trim

Place the 17-inch square on the work surface with its right side facing up. Pin the trim around the entire perimeter of the square. The trim should point inward toward the square's center and overlap it, with the sewing band sitting along the outer edge of the square. Place the two trim ends so they meet flush against each other, forming one unbroken band around the square.

Step 7: Pin and Arrange

Pin one rectangle to the square. The rectangle's right side should face the square's right side, with the fabric's wrong side toward you. Position the rectangle so that its finished edge — the one you already stitched — lands near the middle of the pillow.

Step 8: Line Up the Edges

Match up the raw edges of the rectangle and the square and pin them carefully, keeping the trim tucked inside the layers formed by the two fabric pieces. As you pin, capture all three layers — square, trim and rectangle — and remove the pins that were holding the trim as you go. Then pin the second rectangle to the opposite side of the square, again placing its finished edge near the middle. The finished edges of the two rectangles will overlap at the center of the pillow.

Step 9: Finish the Envelope Pillow Cover

Stitch around the entire pillow on the sewing machine. Treat the trim's sewing band as the seam allowance. Measure that sewing band, then position the sewing machine's presser foot the same distance from the pillow's raw edges. Pull out pins as you sew so you don't break the needle. Turn the cover right side out and slip in the pillow form.